Franz Beckenbauer faces the prospect of being fined for failing to assist the investigation into alleged corruption at Fifa.

According to the German newspaper Die Welt, Fifa’s ethics commission is considering sanctioning the former World Cup winner for failing to answer questions about his role in the decision to host the 2018 and 2022 World Cups in Russia and Qatar.

Beckenbauer, who left Fifa as an executive in 2011 but is still associated with the organisation as a “special adviser”, has come under increasing scrutiny since the Sunday Times published emails which appear to show that secret payments helped Qatar to win its World Cup bid.

Unlike the Uefa president Michel Platini, Beckenbauer has so far refused to declare which country he voted for in the bid for the 2022 World Cup.

Talking about the US prosecutor Michael Garcia, who was charged with investigating allegations of corruption in 2012, a “high-up source within Fifa” told Welt: “I don’t think Garcia will show any restraint when dealing with Beckenbauer. An American prosecutor won’t care whether he is a German national icon, a German or not.”

The same source said it was “highly likely” that Garcia would call for a fine against Beckenbauer. “Anything else would make our ethics code look absurd.”

Beckenbauer claims that he did not respond to the interview request because he didn’t understand all of the questions sent to him in English. “Therefore I politely requested a meeting in which we could talk about the matter in German. That was apparently not desired. That aside I wouldn’t be able to contribute anything to clear up the matter anyway.”

The former Germany player, who won World Cups as a player in 1974 and as a coach in 1990, has denied that his vote was influenced by Qatari lobbying or that he has ever worked on behalf of Mohamed bin Hammam, the then Fifa executive member for Qatar.

The media have reported that Beckenbauer repeatedly visited the emirate on the Persian Gulf before and after Qatar won the bid in 2010. In October 2009 Beckenbauer is said to have accepted an invitation by Bin Hammam upon a recommendation by his friend and adviser, the German sports functionary Fedor Radmann. Since Radmann was at the time lobbying on behalf of Australia’s bid for the World Cup, it had until now been assumed that Beckenbauer had voted for Australia, who had only managed to get a single vote.

In June 2011 Beckenbauer visited Qatar as part of a business delegation representing the Hamburg-based ship-owning company ER Capital Holding – a trip that German media say was also arranged by Bin Hammam. Beckenbauer’s involvement with the shipping company had previously not been widely known, but both the former player’s management and ER Capital Holding confirmed that he had worked as an “adviser and ambassador” for the company between April 2011 and March 2014.

Beckenbauer’s role as an ambassador for the Association of Russian Gas Producers (RGO), meanwhile, has been well-documented since 2012. Russia won its bid to host the 2018 World Cup in December 2010. In this instance, too, Beckenbauer has so far refused to declare which country he backed.

The former president of the German football association, Theo Zwanziger, said on Tuesday he believed it was possible to Beckenbauer could be officially questioned as part of the investigation. “If you read the ethics rules, there will come a point where you can ask questions,” Zwanziger said in São Paulo. “I am proud of my friendship with him, but I also know that Franz Beckenbauer is a businessman.”